78612881 has 8 divisors (see below), whose sum is σ = 81469800. Its totient is φ = 75765760.

The previous prime is 78612851. The next prime is 78612887. The reversal of 78612881 is 18821687.

It can be written as a sum of positive squares in 4 ways, for example, as 55726225 + 22886656 = 7465^2 + 4784^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78612881 - 2⁶ = 78612817 is a prime.

It is a super-2 number, since 2×78612881² = 12359970118240322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78612887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16475 + ... + 20703.

It is an arithmetic number, because the mean of its divisors is an integer number (10183725).

Almost surely, 2^78612881 is an apocalyptic number.

It is an amenable number.

78612881 is a deficient number, since it is larger than the sum of its proper divisors (2856919).

78612881 is a wasteful number, since it uses less digits than its factorization.

78612881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4899.

The product of its digits is 43008, while the sum is 41.

The square root of 78612881 is about 8866.3905282815. The cubic root of 78612881 is about 428.3820230937.

The spelling of 78612881 in words is "seventy-eight million, six hundred twelve thousand, eight hundred eighty-one".